Percutaneous transluminal balloon pulmonary valvuloplasty using domestic balloon catheter for congenital pulmonary valve stenosis in children

OBJECTIVE

To estimate the effect of percutaneous balloon pulmonary valvuloplasty (PBPV) using domestic balloon catheter for congenital pulmonary valve stenosis (PVS) in infants and children.

PATIENTS AND METHODS

The data of 70 patients aged from 1.5 to 12 years (mean 5.5 +/- 3.4 years) who underwent PBPV using domestic balloon catheter for PVS in our institution were reviewed. Sixty-six patients had dome-shaped valve stenosis, and 4 had displastic valve stenosis. SaO2 reduced in 5 patients and associated open foramen ovale was noted in 23. Predilatation, right ventricular systolic pressure ranged from 60 to 234 mmHg (mean 115.75 +/- 36.15 mmHg). The systolic gradient (delta P) from right ventricle to pulmonary artery was 89.92 +/- 38.25 mmHg. Balloon diameter was selected 120%-142% of pulmonary valve annulus diameter (mean 132%). All patients were followed up for 3 months-4 years by means of clinical examination. ECG, 2D-UCG, and Doppler-UCG.

RESULTS

After dilatation, delta P reduced from 89.92 +/- 38.25 to 14.65 +/- 11.40 mmHg (P < 0.001). The rate of decrease in transvalve gradient (delta P) was 83.7%. No patients experienced procedure-related events. Mid-term follow-up showed that no patients had clinical and instrumental complications. Doppler and ECG analyses showed that delta P did not change significantly similar to immediate gradient after PBPV and right ventricular hypertrophy disappeared progressively 6 months after PBPV.

CONCLUSIONS

PBPV is a useful, safe and definitive procedure in the treatment of isolated PVS in infants and children. The properties and features of the balloon catheter produced by Shanghai Med-Tech Factory are similar to those of Med-Tech balloon catheter of U.S.A.

Determination of collagen-proteoglycan interactions in vitro

The objective of this study was to characterize the physical interactions of the molecular networks formed by mixtures of collagen and proteoglycan in vitro. Pure proteoglycan aggrecan solutions, collagen (type II) suspensions and mixtures of these molecules in varying proportions and concentrations were subjected to viscometric flow measurements using a cone-on-plate viscometer. Linear viscoelastic and non-Newtonian flow properties of these solutions and suspensions were described using a second-order statistical network theory for polymeric fluids (Zhu et al., 1991, J. Biomechanics 24, 1007-1018). This theory provides a set of material coefficients which relate the macroscopic flow behavior of the fluid to an idealized molecular network structure. The results indicated distinct differences between the flow properties of pure collagen suspensions and those of pure proteoglycan solutions. The collagen network showed much greater shear stiffness and more effective energy storage capability than the proteoglycan network. The relative proportion of collagen to proteoglycan is the dominant factor in determining the flow behavior of the mixtures. Analysis of the statistical network theory indicated that the collagen in a collagen-proteoglycan mixture enhances molecular interactions by increasing the amount of entanglement interactions and/or the strength of interaction, while aggrecan acts to reduce the number and/or strength of molecular interactions. These results characterize the physical interactions between type II collagen and aggrecan and provide some insight into their potential roles in giving articular cartilage its mechanical behavior.

Transposition of flexor pollicis brevis muscle for reconstruction of thumb opposition. Anatomical study and clinical application

OBJECTIVE

Based on the anatomical study and clinical trial of transposition of the flexor pollicis brevis muscle (M. f. p.b.) for the reconstruction of thumb opposition, we suggested a new method for the treatment of irreparable median nerve injury which causes paralysis of the opponens pollicis and the abductor pollicis brevis muscles (M.a.p.b) and leads to loss of thumb opposition.

MATERIAL AND METHODS

Anatomical study and biomechanic analysis were performed on 20 cadaveric hands and 8 patients who had been treated and followed up on an average for 12 months.

RESULTS

The M.f.p.b. overlaps the M.a.p.b. for about half of its width at the muscle origins and the overlapping reduced to about 1/3 of the width at the muscle belley level. The M.f.p.b. chiefly inserted on the palmar aspect of the base of proximal phalanx. The M.a.p.b. primarily was inserted on the radial side of the first metacarpophalangeal(MP) joint, and the M.f.p.b. was entirely innervated by the deep branch of the ulnar nerve. In an attempt to increase the angle between longitudinal force lines of these two muscles for 7 degrees-9 degrees, we transferred the insertion of the M.f.p.b. to the radial side of the MP joint, so that it gives this muscle the function of opposition. Eight patients were treated and followed up on an average for 12 months. All had fine functional results.

CONCLUSIONS

This method is effective, and least traumatic, and does not need transposition of another tendon.

Inflammatory linear verrucose epidermal nevus coexisting with lichen amyloidosus

The clinical and histopathological findings in a case of inflammatory linear verrucose epidermal nevus coexisting with lichen amyloidosus are presented. A 33-year-old woman had had linear verrucose lesions which were histopathologically compatible with ILVEN, and with which no amyloid deposits were associated, on her left lower leg for 30 years. She had noticed keratotic papules around the verrucose lesions on the left leg for the last 3 years. Histopathology of these papules revealed amyloid deposits in the upper dermis under the hyperkeratotic and acanthotic epidermis. Topical application of DMSO liniment with dexamethasone successfully treated the ILVEN. This remission of both lesions and itching also alleviated the keratotic papules on the left leg.

[Effect of tetramethyl pyrazine on coronary vasoconstriction induced by endothelin-1 in dogs]

The purpose of this study was to determine the antagonistic effect of tetramethyl pyrazine (TMP), a sort of chinese herbal medicine, on coronary vasoconstriction induced by endothelin-1 (ET-1) in closed chest dogs. ET-1 at doses of 50, 75 and 100 pmol was selectively administered into left main coronary artery and coronary angiogram was performed in 1, 3 and 10 minutes after intracoronary administration of ET-1. After a 60 minute interval ET-1 administration and coronary angiogram were repeated in two groups in group A with 5 dogs intravenous infusion of saline solution was administered while in group B with 4 dogs TMP was infused at a dose of 80 mg/kg. Blood pressure of intra-femoral artery, heart rate and ECG were monitored during the experiment. The study demonstrated that coronary vessel diameter significantly decreased by 17% (P < 0.02) in group A and 20% (P < 0.02) in group B, associated with ischemia in ECG (4/5 in group A and 3/4 in group B) after intracoronary administration of ET-1. Endothelin-1 induced coronary vasoconstriction and ischemic changes in ECG were significantly inhibited by intravenous TMP. The coronary diameter increased by 20% (P < 0.03) after administration of TMP, comparing with the control group. Heart rate had an increased response to TMP. In conclusion this study demonstrated that intracoronary administration of ET-1 caused significant myocardial ischemia through coronary vasoconstriction, which was inhibited by TMP. TMP significantly dilated coronary artery.

Many-faceted Rasch calibration of a gross motor instrument

The purpose of this study was to recalibrate a well-developed motor development instrument (Ulrich, 1985) using the many-faceted Rasch model and to examine its advantages and application potential. The instrument was administered to a total of 909 children from a national multistage sampling across 9 states. These children included 451 boys and 458 girls ranging in age from 3-10 years. The instrument was recalibrated using the many-faceted Rasch model with 8 defined facets. The primary advantages of the many-faceted Rasch calibration are (a) that estimations of parameters are independent of both the examinees and testing items employed, (b) that all facets involved in the calibration can be taken into account, (c) that the calibrated facets share the same metric, and (d) that the measurement scales are additive. These advantages, together with goodness-of-fit statistics generated from the calibration, provided a convenient way to examine the appropriateness of the testing items and related facets and to determine examinees' strengths and weaknesses of their measured ability. Finally, through a step-by-step example, it was shown that applying the many-faceted Rasch calibrated instrument can be both simple and practical.

Reduced tumorigenicity of metastatic human lung cancer cell subline (PGCL3) transfected with hRAR beta gene

The recombinant PSG5-RAR beta plasmid and the G418-resistant PSV2 neo plasmid (10.1) were cotransfected into PGCL3 cells by coprecipitation with calcium phosphate. The transfectants CR3 and CR4, which expressed the RAR beta gene, were identified by Northern blot hybridization. The results showed that the in vitro growth and invasion of CR3 and CR4 were dramatically reduced compared to the control-transfected cell (CSV1). Furthermore, the colony-forming abilities in soft agar and the tumorigenicity in nude mice of CR3 and CR4 were abrogated. Our results suggests that RAR beta functions not only as a receptor mediating the RA action, but also as a suppressor in lung tumorigenesis.

Evolutionary strategies for the elucidation of cis and trans factors that regulate the developmental switching programs of the beta-like globin genes

We describe three strategies for the identification of specific cis and trans factors that regulate globin gene expression, all three of which are based on the evolution of the globin genes and their expression patterns. The first approach, phylogenetic footprinting, relies on a search for sequence similarities and is designed to elucidate the factors that control those expression patterns which are shared by orthologous globin genes of all eutherian mammals (e.g., the expression of the epsilon globin genes in the embryonic yolk sac and its repression in fetal and adult hematopoietic tissues). The second approach, differential phylogenetic footprinting, relies on a search for sequence differences. This approach may be of value in identifying the mechanisms underlying the generation of novel expression patterns in specific lineages (e.g., the expression of gamma as a fetal gene in the simian primates in contrast with the embryonic expression of gamma in all other mammals). Finally, motif-based phylogenetic analysis takes into consideration the fact that many transcription factors are quite flexible in the recognition of their cognate sites. The approach allows the detection of functionally conserved binding sites despite their sequence variation.

The N-terminal domain of TFIIB from Pyrococcus furiosus forms a zinc ribbon

The three-dimensional structure of the N-terminal domain of an archaeal TFIIB, which has high sequence homology with eucaryal analogues, is strikingly similar to that of the C-terminal zinc ribbon of the eucaryal transcription elongation factor TFIIB.

Regulation of ionic conductances and gene expression by hypoxia in an oxygen sensitive cell line

We have shown that the PC12 cell line is an excellent model system for investigations of the molecular and cellular processes involved in O2-chemosensitivity. We have identified an O2-sensitive K channel in this cell line that mediates membrane depolarization, an increase in intracellular free Ca2+, and dopamine release during hypoxia. We also presented evidence which shows that expression of the gene for tyrosine hydroxylase, the rate-limiting enzyme in dopamine biosynthesis, is stimulated by reduced O2 tension in PC12 and type I carotid body cells. In addition, we have successfully identified the DNA sequences and trans-acting protein factors that regulate transcription of the TH gene during hypoxia. The mechanisms by which a reduction in O2 tension is transduced into alter cell function including increased gene expression remain unknown. Unpublished results from our laboratory show that the increased TH gene expression during hypoxia does not require activation of the cAMP-PKA signal transduction pathway. We propose that the increase in intracellular free Ca2+ that occurs as a result of membrane depolarization might play an important role. Preliminary findings from our laboratory show that blockade of the voltage operated Ca2+ channel or chelation of intracellular Ca2+ prevent full activation of the TH gene during hypoxia.

A review of the statistical analysis used in papers published in Clinical Radiology and British Journal of Radiology

Statistical analysis such as significance testing have become essential features of published medical studies. This has resulted in an increased frequency with which statistics are used, making the interpretation of scientific publications more difficult. There is an extensive array of tests and techniques. The aim of this study is to identify which statistical tests are used in radiology publications. All major articles published in Clinical Radiology and British Journal of Radiology in one year were reviewed. The frequency of statistical methods used was as follows: no statistical method or descriptive statistics only 103 (47%), one type of statistical method 67 (31%), and two or more methods 47 (22%). Statistics dealing with basic inference, decisions, contingency tables or correlation/regression techniques were found in 124 (53%) in which a procedure had been used. Advanced statistics including receiver operating characteristics (ROC), odds ratio, regression techniques, multiway ANOVA, and nonparametric ANOVA studies accounted for only 41 (19%) in which a procedure had been used. We conclude that descriptive analysis and basic statistical techniques account for most of the statistical tests reported. Physicians should concentrate on improving their understanding of basic statistics but advice should be sought from professionals in the fields of biostatistics and epidemiology as to whether the use of more advanced techniques would be more appropriate.

High affinity YY1 binding motifs: identification of two core types (ACAT and CCAT) and distribution of potential binding sites within the human beta globin cluster

PCR-assisted binding site selection was used to define the sequence characteristics of high affinity YY1 binding sites. Compilation of the sequences of 189 selected oligonucleotides containing high affinity YY1 binding sites revealed two types of core sequence: ACAT and CCAT. ACAT cores were surrounded by other invariant nucleotides, forming the consensus GACATNTT. A search of the 73 kb human beta-like globin cluster with this consensus revealed eight matching motifs, six of which were located within 1-3 kb upstream of the gamma and beta genes. CCAT-type cores were more variable in surrounding sequence context; the consensus VDCCATNWY was found to fit 89% of the selected CCAT-containing oligonucleotides. A search of the human beta globin cluster with CCAT consensus sequences revealed 171 potential YY1 binding sites. Several of these were tested directly in gel shift assays and confirmed as high affinity YY1 binding sites. Finally, a strategy called motif-based phylogenetic analysis was employed to determine which of the 179 total sites are evolutionarily conserved. This analysis permits the detection of functionally conserved binding sites despite sequence differences present between the two species. The 21 conserved sites identified will serve as important starting points in further dissection of the possible role of YY1 in globin gene regulation.

Molecular characterization of the murine thymidylate kinase gene

Thymidylate kinase (TMK) catalyzes an essential reaction of converting dTMP to dTDP, leading to formation of the DNA precursor dTTP. Unlike the preceding enzymes, thymidine kinase and thymdylate synthase, little is known about regulation of TMK after mammalian cells exit from quiescence and enter the cell cycle. In this study, cDNA of murine TMK was isolated and characterized. Murine TMK gene expression in nontransformed BALB/c 3T3 cells was shown to be regulated during Gø to S-phase transit at both mRNA and enzyme activity levels. Its timing was distinctive from that of thymidine kinase and thymdylate synthase. In contrast, the regulation of TMK in response to serum growth factor stimulation was abolished in cells transformed by either SV40 or Kirsten viruses, and tmk expression became constitutively elevated. This finding is in concordance with previous results showing that transformed cells exhibit more relaxed control than normal cells in their initiation of DNA replication.

Calpain inhibitor-induced apoptosis in human prostate adenocarcinoma cells

Although it has been shown that calpains may play a positive role in causing apoptosis of T cells, we report here that, on the contrary, the inhibition of calpain-like activities can induce apoptosis in human prostate cancer cells. Two calpain inhibitors were used to test growth response on prostate cancer cells and showed remarkable cytotoxicity. The cytotoxicity was due to apoptosis as judged by large genomic DNA fragmentation, chromatin condensation and nuclear fragmentation. Furthermore, using gel band shift assays we have demonstrated that calpain inhibitor 1 causes a prolonged elevation of AP-1 protein activity in human prostate cancer cells. The elevation of AP-1 activity appears to be specific, because calpain inhibitor 1 only stimulates AP-1 but not AP-2 and SP-1 activities. We postulate that the sustained increase in AP-1 activity may be involved in apoptosis induced in prostate cells by calpain inhibitors. Our study thus suggests that calpain-like activity may be a potentially therapeutic target for cancer.

[Experimental research and clinical application of allogenic tendon grafting]

Autologous free tendon grafting is a very common treatment for tendon defect of the hand. However, it is difficult to obtain autologous free tendon grafts to repair patients with multiple tendon defects. We described the treatment using deep-freeze-stored tendon with MEM and the establishment of clinical tendon bank. Allograft tendons were used successfully in 15 patients clinically. In the experiments, we also performed a series of studies on immunity and repairing ability of the allogenic tendon grafts. The results indcated that the treatmnet using deep-freeze-stored tendon with MEM could reduce the immunogenicity of allograft. There was no significant difference between autograft and deep-freeze stored allograft 24 weeks after operation, but there was a significant difference in the fresh allograft 3 weeks after grafting. Based on animal experiment, we established a clinical tendon bank. Deep-freeze-stored allogenic tendon grafts can be used successfully in place of autologous tenden grafts in treatment of tendon defect of the hand.

The alpha 6 beta 1 and alpha 6 beta 4 integrins in human prostate cancer progression

Prostatic secretions are formed by glands composed of basal and luminal cells and surrounded by a basal lamina. The normal basal cells express several integrins (extracellular matrix receptors) including alpha 2, 3, 4, 5, 6, v, beta 1 and beta 4. These integrin units are polarized at the base of the cells adjacent to the basal lamina. The integrin alpha 6 beta 4 is associated with hemidesmosomal-like structures. The natural history of prostate cancer involves the presence of prostatic intraepithelial neoplasia (PIN) lesions (considered precursor lesions), carcinoma in situ and invasive carcinoma. Hemidesmosomal proteins and the alpha 3 beta 1 and alpha 6 beta 1 integrins (laminin receptors) are retained in the early PIN lesions. Expression of the integrins alpha 2, alpha 4, alpha 5, alpha v and beta 4 is lost in carcinoma. The alpha 3 beta 1 and alpha 6 beta 1 integrins remain associated with invasive carcinoma, the latter being predominant. Integrin expression in carcinoma is diffuse in the plasma membrane and not restricted to the basal aspects of the cell. The alpha 6 beta 1 integrin is fully functional as judged by an ability to adhere to laminin and contains the wild type alpha 6A cytoplasmic signaling domain. The alpha 6 beta 1 integrin is a leading candidate for conferring the invasive phenotype in prostatic carcinoma. Tumor cells with high expression of alpha 6 integrin are more invasive when tested in a SCID mouse model system. Following intraperitoneal injection, the human tumor cells invade the mouse diaphragm and move through the muscle on the surface of the laminin coated muscle cells. Our current working hypothesis is that the production of alpha 6 beta 1 and laminin in human tumor cells contributes to the invasive phenotype. Invasion could occur on the surfaces of laminin coated structures such as the nerves, blood vessels or muscle and account for the known patterns of human prostate tumor progression. Blockage of the expression or function of alpha 6 beta 1 or laminin or preventing the loss of beta 4 would be essential steps in confining the carcinoma to the prostate gland where conventional treatment has already proven effective.

[Transposition of flexor pollicis brevis muscle for reconstruction of opposition function of the thumb: anatomical study and clinical application]

Anatomical study was performed on 20 cadaveric hands and the results showed that M. flexor pollicis brevis overlap the M. abductor pollicis brevis for about half of its width at their origins and the overlapping reduced to about 1/3 of the width at the muscle belly level. The M. flexor pollicis brevis chiefly inserts on the palmar aspect of the base of proximal phalanges. The M. abductor pollicis brevis primarily inserts to the radial side of MP joints, the M. flexor pollicis brevis is entirely innervated by the deep branch of the ulnar nerve. In order to increase the angle bettween longitudinal force lines of these two muscles for 7-9 degrees, the authors transfered the insertion of the M. flexor pollicis brevis to the radial side of the metacarpal-phalangeal joint, so that it gives this muscle the function of opposition. Eight patients had been treated and followed up on average for 12 months. All had fine functional results. This new methodis effective, least traumatizing and does not need transposition of another tendon.

delta 9-Tetrahydrocannabinol (THC) causes the variable expression of IL2 receptor subunits

Previously, we reported that the cannabinoid delta 9-tetrahydrocannabinol (THC) suppressed interleukin 2 (IL2)-induced proliferation of a cloned, natural killer-like cell line (NKB61A2) and decreased the number of high- and intermediate-affinity IL2 binding sites. However, the surface expression of interleukin 2 receptor alpha (IL2R alpha) chain, as measured by flow cytometry, was increased rather than decreased by THC treatment. This suggested that the drug-induced deficiency in IL2 binding and cell activation involved a defect in the cell-surface expression of IL2R subunits other than the alpha chain. Because the IL2 receptor complex is composed of alpha, beta and gamma chains, we examined the effect of THC treatment on the expression of these chains. In a result consistent with our previous findings, we observed that treatment of NKB61A2 cells with THC increased the cellular immunoprecipitable IL2R alpha protein (p55) and mRNA. Furthermore, the cellular production of IL2R beta chain protein (p75) and mRNA, determined by immunoprecipitation and Northern blotting, respectively, was also increased. The mRNA stability assay showed that THC increased the stability of IL2 beta mRNA, and nuclear run-on experiments suggested that the increase in subunit production was not due to a drug effect on gene transcription. The IL2R gamma chain was also affected by THC treatment in that Northern blotting studies showed a drug-induced decrease in the cellular level of gamma chain mRNA. In addition, THC treatment decreased the 125I-labeled IL2 internalization under high-affinity binding conditions.(ABSTRACT TRUNCATED AT 250 WORDS)

Interference with thymocyte differentiation by an inhibitor of S-adenosylhomocysteine hydrolase

Adenosine deaminase (ADA) deficiency causes severe combined immune-deficiency disease in humans. It is believed that the accumulation of the ADA substrate deoxyadenosine affects T cell development through interference with deoxynucleotide metabolism and/or S-adenosylmethionine-mediated methylation processes. In this study, we used a specific inhibitor of methylation, (Z)-5'-fluoro-4',5'-didehydro-5'-deoxyadenosine (FddA), to study the effect of inhibition of methylation on intrathymic T cell development in a murine model for ADA deficiency. FddA causes inhibition of thymocyte differentiation specifically at the CD8low and CD4CD8 double-positive stages. This inhibition is not due to induction of apoptosis, rather it is a result of specific inhibition of regulation of the levels of the mRNAs coding for TCR and CD4 and CD8 co-receptor molecules that normally occurs at these stages of thymocyte differentiation. We hypothesize that the transcription of these T cell-specific molecules is regulated by a common developmental stimulus involving a S-adenosylmethionine-mediated methylation step. Identification of this step will help in understanding the role of methylation in intrathymic differentiation and will also provide a molecular explanation for the tissue and developmental stage specificity observed in severe combined-immune-deficient patients with ADA deficiency.

Interference with thymocyte differentiation by an inhibitor of S-adenosylhomocysteine hydrolase

Adenosine deaminase (ADA) deficiency causes severe combined immune-deficiency disease in humans. It is believed that the accumulation of the ADA substrate deoxyadenosine affects T cell development through interference with deoxynucleotide metabolism and/or S-adenosylmethionine-mediated methylation processes. In this study, we used a specific inhibitor of methylation, (Z)-5'-fluoro-4',5'-didehydro-5'-deoxyadenosine (FddA), to study the effect of inhibition of methylation on intrathymic T cell development in a murine model for ADA deficiency. FddA causes inhibition of thymocyte differentiation specifically at the CD8low and CD4CD8 double-positive stages. This inhibition is not due to induction of apoptosis, rather it is a result of specific inhibition of regulation of the levels of the mRNAs coding for TCR and CD4 and CD8 co-receptor molecules that normally occurs at these stages of thymocyte differentiation. We hypothesize that the transcription of these T cell-specific molecules is regulated by a common developmental stimulus involving a S-adenosylmethionine-mediated methylation step. Identification of this step will help in understanding the role of methylation in intrathymic differentiation and will also provide a molecular explanation for the tissue and developmental stage specificity observed in severe combined-immune-deficient patients with ADA deficiency.

delta 9-Tetrahydrocannabinol, cytokines, and immunity to Legionella pneumophila

The major psychoactive component of marijuana, delta 9-tetrahydrocannabinol (THC), has been shown to suppress the functions of various immune cells. However, the relationship of these findings to THC-induced suppression of host resistance to infection has not been firmly established. In this report, we review the literature concerning THC's effects on cytokine production and resistance to infection with Legionella pneumophila (Lp). Recent reports have linked THC-induced immunomodulation with drug-induced modulation of the cytokine network. Specifically, THC in vivo suppresses interferon (IFN) production while in vitro modulates the production of tumor necrosis factor (TNF), interleukin-1 (IL-1), interleukin-2 (IL-2), and interleukin-2 receptor (IL-2R). These results suggested that THC treatment might alter host immunity by disrupting the cytokine network. Immunity and resistance to infection with Lp depends upon the activation of killer cells and the stimulation of the cytokine network. THC injection into rodents was observed to augment acute phase cytokine mobilization in response to a primary Lp infection; on the other hand, the drug suppressed the development of protective immunity and resistance to secondary Lp infection by causing a change in the profile of T helper cell cytokines produced by Th1 and Th2 cells. Thus, it appears that THC injection suppresses resistance to Lp infection by disrupting the cytokine network. Regarding the molecular mechanisms of these effects of THC, data is reviewed concerning the role of cannabinoid receptors (CR) in cells of the immune system. In summary, the literature to date supports the role of THC as an immunomodulator capable of suppressing resistance to infection through mechanisms involving alteration of the cytokine network. The role of CR receptors in these events has yet to be determined.

The human glioma pathogenesis-related protein is structurally related to plant pathogenesis-related proteins and its gene is expressed specifically in brain tumors

We report the cloning of a cDNA encoding GliPR (glioma pathogenesis-related protein), a protein that is structurally similar to plant pathogenesis-related proteins. The GLIPR gene is highly expressed in the human brain tumor, glioblastoma multiforme/astrocytoma, but neither in normal fetal or adult brain tissue, nor in other nervous system tumors. GliPR shares up to 50% amino acid (aa) homology with plant pathogenesis-related proteins, group 1, over a region that comprises almost two thirds of the protein. We speculate that there may be functional similarities between the human and plant proteins as well.

[Isolation and characterization of human lung cancer cell subline with different metastatic potential]

Single cell clones were isolated from metastatic human lung giant cell carcinoma (PG) using limited dilution method. After preliminary screening by in vitro invasion assay, tumorigenicity and spontaneous metastasis assay in nude mice, three cloned PG cell sublines (PGBE1, PGCL3 and PGLH7) were selected for further observation on morphology, chromosome number, in vitro growth and invasion assays, tumorigenicity and spontaneous metastasis to lung and lymph nodes in nude mice. We found that there was some difference on spontaneous metastasis to lung and lymph nodes in nude mice and in vitro invasive abilities between PGBE1 and PGLH7. But there were no obvious differences in other biological features among the three sublines. The results show that the PG cell line consists of different subpopulations of cells with different metastatic properties. These sublines may be valuable for further study on the molecular mechanisms of cancer metastasis.

Randomized case-controlled trial of oral low-dose acyclovir for prevention of virus infections in recipients of renal allografts

A randomized case-controlled trial of oral low-dose acyclovir (600-800 mg per day) has been conducted for the prevention of virus infections in 66 recipients of renal allografts since 1990. In comparison with the untreated controls, acyclovir could prevent herpes virus simplex (HSV), reduce morbidity of pneumonia from 10 cases (30%) to 3 cases (9%) (P < 0.05) and lower CMV-IgM positive rate from 30% to 12%. Serum Cr and BUN in acyclovir group were lower than those in control group. These results strongly suggested that oral administration low-dose acyclovir could prevent virus infections after renal transplantation.

Cluster analysis of levels of body fatness in children

The purpose of this study was to examine, using cluster analysis, the levels of body fatness as defined in the current national programs for children and youth fitness. A total of 1,056 examinees were drawn randomly from the published data of the National Children and Youth Fitness Study II, with 525 boys and 531 girls, ages 6 to 9 years. Their triceps and medial calf skinfold measures were used for the cluster analysis, including both the kth nearest-neighbor and the Ward's minimum variance procedures. Although multimodal clusters were found at four age groups according to the kth nearest-neighbor procedure, the Ward procedure and plotting of these clusters did not support their existence. It was concluded that the levels of body fatness reported in the current national children and youth fitness programs were arbitrarily defined.

Id gene expression during development and molecular cloning of the human Id-1 gene

Id genes encode helix-loop-helix proteins that inhibit transcription by forming inactive heterodimers with basic helix-loop-helix (bHLH) proteins. bHLH proteins normally form either homodimers or heterodimers with other bHLH proteins and bind to a DNA sequence element activating transcription. Id-containing heterodimers are inactive because Id proteins lack the basic amino acid region necessary to form a DNA-binding domain. We have examined the relative levels of Id-1 and Id-2 mRNA during normal development and in malignant tissues. In the course of these experiments we cloned and sequenced the human Id-1 cDNA. Two related cDNA molecules encoding human Id-1 mRNAs were identified. Id-1a is a cDNA of 958 nucleotides and can encode a protein of 135 amino acids. Id-1b cDNA is 1145 nucleotides, can encode a protein of 149 amino acids, and appears to be a splice variant of Id-1a. The amino acid sequence of human Id-1 is greater than 90% homologous to that of mouse Id-1. The patterns of Id-1 and Id-2 expression during mouse development vary widely, and we detected Id-1 expression in human fetal and adult tissues from lung, liver, and brain. High Id-1 mRNA expression was found in many human tumor cell lines, including those isolated from nervous system tumors. We mapped Id-2 to human chromosome 2p25.

[Isolation and identification of a pathogen of grasshoppers]

A pathogen was isolated from natural dead pests of Ceracris kiangsu in Geleshan farm of Chongqin. Its pathogenecity was confirmed by the law of KOCK. It was identified as Pseudomonas pseudoalcaligenes according to its physiological and biochemical properties as well as the G + C content of DNA (63.73mol%). The results of preliminary bioassay show that the pathogen can infect the grasshoppers and Ceracris kiangsu, and also can infect other pests of grassland in a certain extent.

[Changes and trend prediction in cancer morbidity of urban residents in Beijing]

Data from a long-term cancer morbidity registry and notification system were analyzed dynamically. A theoretical model of grey system was established based on time-series changes in cancer morbidities to predict its trend by the year of 2001 in Beijing. Results show cancer morbidities in Beijing will increase yearly from 1991 to 2001, and overall morbidity rate of malignant tumor will increase to 179.9/100,000 from 162.5/100,000. Proportions of malignant tumor in different sites will change greatly. Morbidities of lung cancer and breast cancer will increase rapidly, of liver and colon-rectal cancer shoes an increasing trend, too, of esophageal and cervical cancer will decline steadily, and of stomach cancer will begin to decline. All these facts laid a scientific basis for the study on cancer prevention and control.

A novel gene, AF1q, fused to MLL in t(1;11) (q21;q23), is specifically expressed in leukemic and immature hematopoietic cells

Translocations involving chromosomal band 11q23 are associated with leukemias. These translocations fuse the MLL, a gene with sequence homology to the Drosophila trithorax, to genes from a number of other chromosomal loci. We have characterized two t(1;11)(q21;q23) translocations that fuse the MLL gene to a novel gene, AF1q on chromosomal band 1q21, in two infants with acute myelomonocytic leukemia (AMMOL). In one of these patients, der(11) represents an inframe fusion of the N-terminal portion of MLL gene to the complete AF1q open reading frame, whereas der(1) does not give rise to an open reading frame. This observation suggests that the N-terminal portion of MLL gene is critical for leukemogenesis in translocations involving band 11q23. The predicted wild-type AF-1q product is a 9-kD protein with no similarity to any other protein in the data banks. The AF1q mRNA is highly expressed in the thymus but not in peripheral lymphoid tissues. In contrast to its restricted distribution in normal hematopoietic tissue, AF1q was expressed in all leukemic cell lines tested.

Melatonin protects primary cultures of cerebellar granule neurons from kainate but not from N-methyl-D-aspartate excitotoxicity

the antiexcitotoxic efficacy of melatonin, a putative endogenous hydroxyl radical scavenger, was studied in primary cultures of rat cerebellar granule neurons. Excitotoxicity was induced in 7- to 9-day-old cultures by an exposure to glutamate (15 min in the absence of magnesium) or to glutamate receptor agonists, kainate (30 min), and N-methyl-D-aspartate (60 min in the absence of magnesium). Thereafter, cultures were returned to the culture-conditioned medium for 18 h at the end of which time viability was assessed by quantitative staining with 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide. Cotreatment with melatonin (500 microM) protected the neurons completely from the toxicity of kainate (up to 1 mM) and shifted the ED50 for glutamate from 55 +/- 2.6 to 97 +/- 3.6 microM. Melatonin cotreatment was ineffective in protecting the neurons from N-methyl-D-aspartate toxicity. When melatonin was added to the cultures only before or after kainate treatment, there was no resultant protection from kainate toxicity. The neuroprotective effect of melatonin does not appear to be related to the direct action of melatonin on ionotropic glutamate receptors. That is, the kainate-stimulated inward currents measured by a patch-clamp technique in voltage clamped neurons and the kainate-stimulated increase in free cytosolic calcium measured at the single-cell level using digital imaging fluorescent microscopy with fura-2 were not affected by melatonin. Moreover, the binding of [3H]glutamate to rat cerebellar membranes was not competed off by melatonin. Further studies are needed to evaluate the pharmacologic relevance of the neuroprotective action of melatonin.

[The expression of Cath-D, c-erbB-2 and EGFR in breast cancer and its correlation to lymphatic metastasis]

The expression of Cath-D c-erbB-2 and EGFR in breast cancer and its correlation of lymphatic metastases were studied in 277 cases by immunohistochemical technique. Positive staining of Cath-D was detected in 107 cases (38.62%), of which, 89 cases (83.17%) had documented metastasis in the lymph nodes. One hundred and seventy cases (61.38%) stained negative for Cath-D, of which 64 cases (37.64%) had detectable lymphatic metastases. There was a significant difference in the rate of the lymphatic metastases between the Cath-D positive and Cath-D negative groups (P < 0.0001). Fifty-six out of 107 Cath-D positive cases (52.34%) were c-erbB-2 positive as well. However, only 27 out of 170 Cath-D negative cases (15.88%) were c-erbB-2 positive. The positive rate of c-erbB-2 in Cath-D positive group was significantly different from that of Cath-D negative group (P < 0.0001). Among those 107 Cath-D positive cases, 49 cases (45.79%) were EGFR positive. Only 24 cases (14.12%) were EGFR positive among the 170 Cath-D negative cases. The positive rate of EGFR between these two groups was also significantly different (P < 0.0001). The results suggest that Cath-D status can be used as an indicator of the aggressiveness of the breast cancer. Breast cancer cases with a positive Cath-D staining are more likely to have lymphatic metastases and a poor prognosis. Therefore, alternative therapeutic strategies and close follow-ups are needed for these patients.

Differential display using one-base anchored oligo-dT primers

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Ras activation of genes: Mob-1 as a model

The ras oncogenes function by indirectly controlling expression of a subset of yet-undefined genes that are crucial for cell growth and differentiation. In a differential display strategy, numerous genes were identified on the basis of their differential expression in rat embryo fibroblasts transformed by the cooperation of mutant Ha-ras and p53 genes. We demonstrate here that one such gene, designated mob-1, is a downstream target of the Ras signaling pathway. The 417-bp mob-1 promoter, which contains dual NF-kappa B and AP-1 binding sites, confers the Ras inducibility. Oncogenic Ras as well as serum growth factors that activate endogenous Ras can induce mob-1 expression, but with a fundamental difference in that the oncogenic induction is constitutive whereas the serum induction is transient. mob-1 encodes a small secretory protein with a high degree of homology to IP-10, a member of a proinflammatory cytokine family. These findings link chronic inflammatory response to constitutive ras activation and tumorigenesis. Mob-1 may serve as a secreted marker for oncogenic Ha-ras mutations.

Family A and family B DNA polymerases are structurally related: evolutionary implications

In order to establish the evolutionary relationship between the family A and B DNA polymerases, we have closely compared the 3'-->5' exonuclease domains between the Klenow fragment of E.coli DNA polymerase I (a family A DNA polymerase) and the bacteriophage PRD1 DNA polymerase, the smallest member of the DNA polymerase family B. Although the PRD1 DNA polymerase has a smaller 3'-->5' exonuclease domain, its active sites appear to be very similar to those of the Klenow fragment. Site-directed mutagenesis studies revealed that the residues important for the 3'-->5' exonuclease activity, particularly metal binding ligands for the Klenow fragment, are all conserved in the PRD1 DNA polymerase as well. The metal binding ligands are also essential for the strand-displacement activity of the PRD1 DNA polymerase. Based on these results and the studies by others in various systems, we conclude that family A and B DNA polymerases, at least in the 3'-->5' exonuclease domain, are structurally as well as evolutionarily related.

[The observation of the bulbar conjunctival microcirculation in patients with retinitis pigmentosa]

The detection of the bulbar conjunctival microcirculation (BCM) of 73 cases (146 eyes) with retinitis pigmentosa (RP) showed that there were some abnormal changes of BCM in the pathologic progress of RP. The older the patient, the longer the disease history and the more the loss of visual field, the more serious the abnormal changes of BCM. The disease in male patients was in general more serious than in female patients. Its characteristics were the followings: increase in the number of tortuous vessels; the different widths of vessels in a few cases; obvious increase of microangioma; abnormal proportion of artery to vein; decelerated blood flow and aggregated erythrocytes. Some abnormal changes in the nailfold microcirculation (left ring finger) were observed in the meantime, and compared with those in the BCM of 56 cases. It was found that they were positively interrelated (gamma's = 0.9965, P < 0.001).

Mutagenesis of a highly conserved lysine 340 of the PRD1 DNA polymerase

All known family B DNA polymerases contain a conserved region of amino acids, KX6-7YG, which appears to be correspond to the 'finger' alpha helix O of the Klenow fragment of E. coli DNA polymerase I, a family A DNA polymerase. Toward the goal of establishing the evolutionary relationship between the family A and B DNA polymerases, we have employed site-directed mutagenesis to access the functional role of the invariant amino acid lysine-340 of the PRD1 DNA polymerase. We have replaced the lysine-340 with three amino acids: histidine, asparagine and glutamic acid, respectively. Mutant DNA polymerases were overexpressed and purified to near homogeneity. Our results showed that the modification of the lysine-340 of the PRD1 DNA polymerase abolishes the polymerase activity without affecting the 3' to 5' exonuclease activity. These results support the proposal that the KX6-7YG motif of the family B DNA polymerases may be analogous to the KX7YG motif of the family A DNA polymerases, suggesting that two family DNA polymerases share a common ancestor.

Purification and characterization of PRD1 DNA polymerase

A small lipid-containing bacteriophage PRD1 encodes a DNA polymerase that utilizes a protein primer for the initiation of DNA replication. The purification of the PRD1 DNA polymerase has been hampered by the insolubility of the overexpressed enzyme in Escherichia coli cells. We have developed a simple and rapid procedure for purification of the overexpressed PRD1 DNA polymerase. This method is based on guanidine hydrochloride denaturation and renaturation of the insoluble PRD1 DNA polymerase overexpressed in E. coli containing the recombinant plasmid pEJG. The purified DNA polymerase was extensively characterized and found to be indistinguishable from the normal soluble PRD1 DNA polymerase as judged by enzymatic properties. These properties include: protein-primed initiation of PRD1 DNA replication, strand-displacement DNA synthesis, DNA polymerase processivity, 3' to 5' exonuclease activity and filling-in repair type DNA synthesis. Furthermore, the kinetic parameters determined for dNTPs and primer-terminus were of the same order of magnitude. The availability of a simple purification procedure for the PRD1 DNA polymerase should permit detailed structure-function analysis of this enzyme.

Rasch partial credit analysis of gross motor competence

The purpose of this study was to introduce a model for measurement of partial credit for the assessment of gross motor competence. Four different striking tasks were administered to a total of 128 children, ages 3 to 9 years, consisting of 64 boys and 64 girls. The partial scores were analyzed using the Rasch Partial Credit model. Satisfactory fit of model and data was obtained for Task 1 and Task 4. Step difficulties estimated for Tasks 1 and 4 ranged from 5.61 to 5.50. The average ability of the children was 0.09 (SD = 2.95). The first and second steps of Tasks 1 and 4 were easy for the children and the fourth step was difficult for them. The major advantage of using the Rasch Partial Credit analysis is that motor process measures can be calibrated and analyzed by a quantitative model with advanced test characteristics.

Anisotropic viscoelastic shear properties of bovine meniscus

The objectives of this study were to determine the viscoelastic shear properties of bovine menisci and to examine those variations with respect to the structural organization of the tissue. Disc shaped meniscal specimens were subjected to: (1) oscillatory shear deformation over a physiological range of frequencies (1-100 rads per second), and (2) shear deformation in the range of infinitesimal strains (0.005-0.05 rad). The dynamic shear modulus and the transient shear stress relaxation function were determined from the experiments. The dynamic shear modulus was measured at 3 levels of compressive strain (7%, 10%, 13%). Directional variations in shear properties were examined by testing axially, radially, and circumferentially oriented specimens. The experiment showed that meniscal tissue exhibits intrinsic viscoelastic behavior in shear that depends on frequency, shear strain, and compressive strain. Shear anisotropy is evident and is dependent upon compression. At low compressive strains (< or = 10%), the circumferentially oriented specimens were found to be stiffer in shear than the axially and radially oriented specimens. At high compressive strains (> 10%), no statistically significant difference was found between the circumferentially and axially oriented specimens. These results suggest that the anisotropic shear properties of the meniscus are related to the collagen fiber orientation within the meniscus.